Display device

ABSTRACT

A display device including: an image display section in which unit pixels each composed of a plurality of sub-pixels corresponding to a plurality of colors are arranged; and an optical element having a window section allocating light emitted from the image display section in units of the sub-pixels to a plurality of viewpoints, wherein a color arrangement of the sub-pixels of the image display section or an arrangement of the window section of the optical element is set such that, when the image display section is viewed from each of the plurality of viewpoints, in an arrangement of colors of light allocated by the window section of the optical element, a same color is not arranged linearly in a predetermined number of sub-pixels or more in succession in any of a row direction, a column direction, and an oblique direction.

CROSS REFERENCES TO RELATED APPLICATIONS

The present invention is a Continuation of application Ser. No.13/609,699, filed Sep. 11, 2012, and contains subject matter related toJapanese Patent Application JP 2011-230300 filed in the Japanese PatentOffice on Oct. 20, 2011, the entire contents of which being incorporatedherein by reference.

BACKGROUND

The present disclosure relates to a display device. There are displaydevices for realizing a stereoscopic vision when an image observerobserves two or more images with parallax or disparity (which images maybe referred to simply as “parallax images”). Methods for realizingstereoscopic vision in display devices of this kind include varioussystems. Among the various systems, systems such as a barrier system anda lens system are the mainstream systems.

In cases of these systems, a special optical element enabling parallaximages to be perceived three-dimensionally, that is, an optical elementsuch as a barrier, a lens, or the like is disposed on the displaysurface side of an image display section, and the optical elementcontrols the direction of light emitted from the image display section.Meanwhile, on the side of the image display section, control isperformed so as to allocate pixels according to the positions ofviewpoints: for example, for a right eye and a left eye in a case ofstereoscopic images (three-dimensional images) with a binocularparallax; and for a first viewpoint, a second viewpoint, a thirdviewpoint, . . . in a case of stereoscopic images with multipleparallaxes. Therefore, stereoscopic images are degraded in resolutionbecause the number of pixels for each viewpoint in the stereoscopicimages is reduced as compared with a planar image (two-dimensionalimage) displayed by the same display device.

As a measure against this, in a related art, degradation in resolutionin a horizontal direction is suppressed by forming light emitting pixelsof a backlight having a function of a barrier in stepwise oblique lightemitting pixel columns (see Japanese Patent Laid-Open No. 2010-44181,for example).

SUMMARY

The above-described related art in which the barrier is in a stepwiseform does not present a problem when a natural image is displayed, butdeteriorates visibility more than degradation in resolution when animage composed of a monotone set of pixels such as a geometric figure ora character is displayed. This is because when an image composed of amonotone set of pixels is allocated to viewpoints, information in a samecolumn, row, oblique direction, or the like may lack, thus causing aloss of a part of an image as well as coloring, absence of information,and the like in a case of a geometric figure or a character.

Incidentally, while the above description refers to a display devicedisplaying stereoscopic images (three-dimensional images), similarprinciples apply to display devices capable of displaying differentimages according to an angle at which the image display section isviewed by controlling the direction of light emitted from an imagedisplay section with an optical element such as a barrier or the like.The above problems are therefore true for not only display devicesdisplaying stereoscopic images but also display devices displayingdifferent images according to a viewing angle.

It is therefore desirable to provide a display device that can improvevisibility at a time of displaying images composed of a monotone set ofpixels, such as a geometric figure or a character in particular.

According to an embodiment of the present disclosure, there is provideda display device including: an image display section in which unitpixels each composed of a plurality of sub-pixels corresponding to aplurality of colors are arranged; and an optical element having a windowsection allocating light emitted from the image display section in unitsof the sub-pixels to a plurality of viewpoints, wherein a colorarrangement of the sub-pixels of the image display section or anarrangement of the window section of the optical element is set suchthat, when the image display section is viewed from each of theplurality of viewpoints, in an arrangement of colors of light allocatedby the window section of the optical element, a same color is notarranged linearly in a predetermined number of sub-pixels or more insuccession in any of a row direction, a column direction, and an obliquedirection.

Here, “row direction” refers to a direction in which pixels are arrangedin pixel rows, that is, a direction along the pixel rows. “Columndirection” refers to a direction in which pixels are arranged in pixelcolumns, that is, a direction along the pixel columns.

In the display device of the above-described constitution, when theimage display section is viewed from each of the plurality ofviewpoints, if a same color is not arranged linearly in a predeterminednumber of sub-pixels or more in succession in any of the row direction,the column direction, and the oblique direction within the arrangementof colors of light allocated by the window section of the opticalelement, the absence of information, for example, in a same column, row,and oblique direction can be avoided when allocating images composed ofa monotone set of pixels to viewpoints.

The display device according to this embodiment of the presentdisclosure can prevent the absence of information, for example, in asame column, row, and oblique direction at a time of allocating imagescomposed of a monotone set of pixels to viewpoints. Therefore,visibility can be improved when displaying images composed of a monotoneset of pixels such for example as a geometric figure or a character inparticular.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic perspective view of a stereoscopic image displaydevice of a parallax barrier system according to an embodiment of thepresent disclosure where constituent elements thereof are virtuallyseparated from each other;

FIG. 2 is a horizontal sectional view of the stereoscopic image displaydevice according to the embodiment;

FIGS. 3A and 3B are schematic diagrams for assistance in explainingprinciples of the parallax barrier system in a case of a binocularparallax;

FIG. 4 is a diagram for assistance in explaining the allocation ofpixels in a pixel row/column to respective viewpoints in amulti-parallax system;

FIGS. 5A, 5B, and 5C are diagrams for assistance in explaining problemsin a case of three viewpoints when the color arrangement of the pixelsof an image display section and the arrangement of the transmittingsections of a parallax barrier have regularity;

FIGS. 6A and 6B are diagrams showing an image displayed in 2D displayand in 3D display, respectively, in a case where a Chinese character(kanji) composed of a square and a plus therein (□ with + therein) isdisplayed on a screen in black with a background color of green;

FIGS. 7A, 7B, and 7C are diagrams for assistance in explaining problemsin a case of four viewpoints when the color arrangement of the pixels ofthe image display section and the arrangement of the transmittingsections of the parallax barrier have regularity;

FIGS. 8A, 8B, and 8C are diagrams for assistance in explaining problemsin a case of four viewpoints when the pixels of the image displaysection are in a stripe arrangement and the transmitting sections of theparallax barrier are in a delta arrangement;

FIGS. 9A, 9B, and 9C are diagrams for further consideration of the caseillustrated in FIGS. 7A to 7C;

FIGS. 10A and 10B are diagrams for assistance in explaining a relatedart and the present embodiment, respectively, in a case of N viewpointsas a common example;

FIGS. 11A, 11B, and 11C are diagrams for assistance in explainingrelation between the color arrangement of the pixels of the imagedisplay section and the arrangement of the transmitting sections of theparallax barrier in the case of four viewpoints according to a firstexample;

FIGS. 12A, 12B, and 12C are diagrams for assistance in explainingrelation between the color arrangement of the pixels of the imagedisplay section and the arrangement of the transmitting sections of theparallax barrier in the case of four viewpoints according to a secondexample;

FIGS. 13A, 13B, and 13C are diagrams for assistance in explainingrelation between the color arrangement of the pixels of the imagedisplay section and the arrangement of the transmitting sections of theparallax barrier in the case of four viewpoints according to a thirdexample;

FIGS. 14A, 14B, and 14C are diagrams for assistance in explainingrelation between the color arrangement of the pixels of the imagedisplay section and the arrangement of the transmitting sections of theparallax barrier in the case of four viewpoints according to a fourthexample;

FIGS. 15A, 15B, and 15C are diagrams for assistance in explainingrelation between the color arrangement of the pixels of the imagedisplay section and the arrangement of the transmitting sections of theparallax barrier in the case of four viewpoints according to a fifthexample;

FIGS. 16A, 16B, and 16C are diagrams for assistance in explainingrelation between the color arrangement of the pixels of the imagedisplay section and the arrangement of the transmitting sections of theparallax barrier in the case of four viewpoints according to a sixthexample;

FIGS. 17A, 17B, and 17C are diagrams for assistance in explainingrelation between the color arrangement of the pixels of the imagedisplay section and the arrangement of the transmitting sections of theparallax barrier in the case of four viewpoints according to a seventhexample;

FIGS. 18A, 18B, 18C, and 18D are diagrams for assistance in explainingan eighth example;

FIGS. 19A, 19B, and 19C are diagrams for assistance in explainingrelation between the color arrangement of the pixels of the imagedisplay section and the arrangement of the transmitting sections of theparallax barrier in the case of four viewpoints according to a ninthexample; and

FIGS. 20A and 20B are diagrams showing color arrangements of the pixelsof the image display section according to modifications.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present disclosure will hereinafter be described on the basis ofembodiments thereof with reference to the drawings. The presentdisclosure is not limited to the embodiments, and various numericalvalues and the like in the embodiments are examples. In the followingdescription, identical elements or elements having identical functionsare identified by the same reference numerals, and repeated descriptionthereof will be omitted. Incidentally, the description will be made inthe following order.

1. Display Device According to Embodiment of Present Disclosure, GeneralDescription 2. Stereoscopic Image Display Device According to Embodimentof Present Disclosure [Display Device According to Embodiment of PresentDisclosure, General Description]

A display device according to an embodiment of the present disclosureincludes an image display section in which unit pixels each composed ofa plurality of sub-pixels corresponding to a plurality of colors arearranged and an optical element for allocating light emitted from theimage display section in units of the sub-pixels to a plurality ofviewpoints, or in other words, allocating the sub-pixels according tothe positions of the plurality of viewpoints. A unit pixel is one unitfor forming a color image, and is composed of three sub-pixelscorresponding to the three primary colors of red (R), green (G), andblue (B), for example.

The unit pixels are not limited to the configuration composed of acombination of sub-pixels corresponding to the three primary colors ofRGB. The unit pixels can be of a configuration composed of a combinationof sub-pixels corresponding to complementary colors of cyan (C), magenta(M), and yellow (Y) or the like, or of a configuration obtained byfurther adding a sub-pixel corresponding to one color or sub-pixelscorresponding to a plurality of colors to sub-pixels corresponding tothe three primary colors. More specifically, for example, a unit pixelcan be formed adding a sub-pixel corresponding to white (W) to improveluminance, or adding at least one sub-pixel corresponding to acomplementary color of yellow (Y) or another color so as to extend therange of color reproduction.

The display device according to the embodiment of the present disclosuredisplays a plurality of images by allocating light emitted from theimage display section in units of the sub-pixels to a plurality ofviewpoints. An example of a display device of this kind is astereoscopic image display device for realizing a stereoscopic vision byallowing an image observer to observe two or more images having aparallax or disparity (which images may hereinafter be referred tosimply as “parallax images”). Stereoscopic image display devices areroughly classified into an eyeglass system that separates and inputsparallax images into a left eye and a right eye through eyeglasses and anaked-eye system that inputs parallax images into a left eye and a righteye through a special optical element without using eyeglasses.

In a stereoscopic image display device of the naked-eye system, aspecial optical element allocates light emitted from the image displaysection in units of sub-pixels to a plurality of viewpoints, or in otherwords, allocates the sub-pixels according to the positions of theplurality of viewpoints. It is therefore possible for an image observerto perceive parallax images three-dimensionally (to provide the image asa stereoscopic image). The stereoscopic image display device using thisspecial optical element includes various systems such as a parallaxbarrier system using a parallax barrier as the special optical element,a lenticular lens system using a lenticular lens as the special opticalelement, a liquid crystal lens system using a liquid crystal lens as thespecial optical element, and so on.

Examples of a display device that display a plurality of images byallocating light emitted from an image display section in units ofsub-pixels to a plurality of viewpoints include not only stereoscopicimage display devices but also multiple-screen display devices (forexample, so-called two-screen display devices). A multiple-screendisplay device displays different images depending on an angle at whichan image observer observes an image display section, and therebyseparately provides a plurality of two-dimensional images displayed bythe image display section to a plurality of image observers.

A well-known display panel such as a liquid crystal display panel, anelectroluminescence display panel, a plasma display panel, or the likecan be used as the image display section used in the display deviceaccording to the embodiment of the present disclosure. A transmissivetype liquid crystal display panel is used as an image display section ina stereoscopic image display device according to another embodiment tobe described later.

The liquid crystal display panel includes for example a front panel(such as a substrate or a color filter substrate) including atransparent common electrode, a rear panel (such as a substrate or anarray substrate) having transparent pixel electrodes, and a liquidcrystal material disposed between the front panel and the rear panel.The operation mode of the liquid crystal display panel is notspecifically limited. The liquid crystal display panel may be configuredto be driven in the so-called TN mode, or may be configured to be drivenin the VA mode or IPS mode.

When the number M×N of pixels of the image display section is denoted as(M, N), examples of values of (M, N) are some of the resolutions forimage display, specifically VGA (640, 480), S-VGA (800, 600), XGA (1024,768), APRC (1152, 900), S-XGA (1280, 1024), U-XGA (1600, 1200), HD-TV(1920, 1080), and Q-XGA (2024, 1536) as well as (1920, 1035), (720,480), (1280, 960), and so forth. However, the values of (M, N) are notlimited to these values.

A well-known illuminating device can be used as a backlight section(illuminating section) for illuminating the transmissive type liquidcrystal display panel from a rear surface side. The configuration of theilluminating section is not specifically limited. The backlight sectioncan be composed of well-known members such as a light source, a prismsheet, a diffusion sheet, a light guide plate, etc.

A driving circuit for driving the image display section can be formed ofvarious circuits including well-known circuit elements.

In the display device according to this embodiment of the presentdisclosure, a color arrangement of the sub-pixels of the image displaysection is set such that, when the image display section is viewed fromeach of the plurality of viewpoints, in the arrangement of colors oflight allocated by a window section of the optical element, a same coloris not arranged linearly in a predetermined number of sub-pixels or morein succession in a row direction, a column direction, or an obliquedirection.

Alternatively, in the display device according to the embodiment of thepresent disclosure, an arrangement of the window section of the opticalelement is set such that, when the image display section is viewed fromeach of the plurality of viewpoints, in the arrangement of colors oflight allocated by the window section of the optical element, a samecolor is not arranged linearly in a predetermined number of sub-pixelsor more in succession in a row direction, a column direction, or anoblique direction.

When a same color is thus not arranged linearly in a predeterminednumber of sub-pixels or more in succession in a row direction, a columndirection, or an oblique direction in each of the arrangements of colorsof light allocated by the window section of the optical element, thatis, in each of the arrangements observed when the image display sectionis viewed from the plurality of viewpoints, absence of information in asame column, row, or oblique direction can be avoided at a time an imagecomposed of a monotone set of pixels is allocated to viewpoints. It istherefore possible to improve visibility of when displaying imagescomposed of a monotone set of pixels, such as a geometric figure or acharacter in particular.

Various kinds of conditions shown in the present specification aresatisfied not only when they hold strictly but also when they hold ineffect. The presence of various variations occurring in design or inmanufacturing is tolerated.

[Stereoscopic Image Display Device According to Embodiment of PresentDisclosure]

As one example of display devices according to embodiments of thepresent disclosure, a stereoscopic image display device will bedescribed in the following. It is supposed that the stereoscopic imagedisplay device of this embodiment is a stereoscopic image display deviceof a parallax barrier system using a parallax barrier as an opticalelement for enabling parallax images perceived (provided) asstereoscopic images by allocating light emitted from an image displaysection in units of sub-pixels to a plurality of viewpoints.

FIG. 1 is a schematic perspective view of the stereoscopic image displaydevice of the parallax barrier system according to the embodiment whereconstituent elements thereof are virtually separated from each other.

As shown in FIG. 1, the stereoscopic image display device 1 according tothis embodiment includes: an image display section 10 capable ofdisplaying a parallax image; a parallax barrier 20 as an optical elementfor allowing the parallax image perceived (provided) as a stereoscopicimage; and a backlight section 30 disposed on the rear surface side ofthe image display section 10.

The image display section 10 is formed of a liquid crystal displaypanel, for example. The liquid crystal display panel is for examplecomposed of a front panel 11, a rear panel 12, and a liquid crystalmaterial (not shown) disposed between the front panel 11 and the rearpanel 12. The front panel 11 has a transparent common electrode providedso as to be common to all pixels. The rear panel 12 has pixels 40arranged therein in the form of a two-dimensional matrix. The rear panel12 has transparent pixel electrodes provided for each pixels 40.

As the parallax barrier 20, there are a variable barrier in whichbarriers (light shielding sections) are formed selectively and a fixedbarrier in which barriers are formed in a fixed state. The variablebarrier functions to allow parallax images perceived as a stereoscopicimage (three-dimensional images) in a state where the barriers areformed, and does not perform this function in a state where the barriersare not being formed. The variable barrier is therefore maintained inthe state where the barriers are not being formed when displaying anordinary planar image (two-dimensional image).

On the other hand, the fixed barrier is always in a state that itfunctions to make parallax images perceived as a stereoscopic image.Thus, when the fixed barrier is used as the parallax barrier 20 in astereoscopic image display device capable of also displaying a planarimage, the image display section 10 displays two images without aparallax as an image for a right eye and an image for a left eye whendisplaying a planar image.

Suppose that a variable barrier is used as the parallax barrier 20 inthe stereoscopic image display device 1 according to the presentembodiment. In addition, suppose that a parallax barrier of a liquidcrystal system that forms barriers (light shielding sections) usingliquid crystals is used as the variable barrier, for example. However,the use of a fixed barrier as the parallax barrier 20 is not excluded.

The parallax barrier 20 of the liquid crystal system includes two glasssubstrates 21 and 22 and a liquid crystal layer 23 formed by sealing aliquid crystal material in a sealed space between the glass substrates21 and 22. A sealing section for sealing the liquid crystal materialbetween the glass substrates 21 and 22 is not shown in order to simplifythe drawing. One of the glass substrates 21 and 22 has stripe-shapedtransparent electrodes formed therein at certain intervals in adirection in which pixels in pixel columns of the image display section10 are arranged (column direction), that is, a vertical direction(Y-direction in FIG. 1). The other one of the glass substrates 21 and 22has a transparent common electrode formed substantially over the entiresurface of the glass substrate.

When a voltage is applied between the stripe-shaped transparentelectrodes and the transparent common electrode in the parallax barrier20 of the liquid crystal system, light shielding sections (barriers) 24are formed in the form of stripes at certain intervals so as tocorrespond to the stripe-shaped transparent electrodes. FIG. 1 shows thelight shielding sections 24 by hatching. Transmitting sections 25 areformed between these stripe-shaped light shielding sections 24. FIG. 1shows the transmitting sections 25 as white stripes. The transmittingsections 25 of the parallax barrier 20 correspond to the window sectionof the optical element for allocating light emitted from the imagedisplay section 10 in units of the pixels (sub-pixels) 40 to a pluralityof viewpoints.

The parallax barrier 20 of the liquid crystal system having theabove-described configuration is used in combination with the imagedisplay section 10, and has functions of the optical element enablingparallax images displayed by the image display section 10 to beperceived three-dimensionally. That is, applying a voltage between thestripe-shaped transparent electrodes and the transparent commonelectrode and thereby alternately forming the stripe-shaped lightshielding sections 24 and the stripe-shaped transmitting sections 25 atcertain intervals, a parallax image displayed by the image displaysection 10 can be perceived (provided) as a stereoscopic image(three-dimensional images) by an image observer.

When no voltage is applied between the stripe-shaped transparentelectrodes and the transparent common electrode, on the other hand, theliquid crystal layer 23 is in a transmitting state (transmittingsections) over the entire surface of the liquid crystal layer 23. Inthis case, the parallax barrier 20 of the liquid crystal system does notperform (does not have) the functions of the optical element enablingparallax images displayed by the image display section 10 to beperceived three-dimensionally. Thus, when no voltage is applied betweenthe stripe-shaped transparent electrodes and the transparent commonelectrode, an ordinary planar image (two-dimensional image) is displayedinstead of a stereoscopic image.

The backlight section 30 is an illuminating section of a surface lightsource type that illuminates the entire surface of the image displaysection 10 from the rear surface side thereof. The configuration of thebacklight section 30 is not specifically limited. The backlight section30 can be composed of well-known members such as a light source, a prismsheet, a diffusion sheet, a light guide plate, and the like. Awell-known light source, such as an LED, a cold-cathode tube, or thelike, can be used as the light source of the backlight section 30. TheLED, in particular, is a light source having a wide range of colorreproduction.

FIG. 2 is a horizontal sectional view of the stereoscopic image displaydevice 1 according to the present embodiment. As shown in FIG. 2, apolarizer 13 is disposed on the rear surface of the image displaysection 10 formed of the liquid crystal display panel, that is, on thesurface of the rear panel 12 on the side of the backlight section 30. Inaddition, polarizers 26 and 27 are respectively disposed on the surfaceof the glass substrate 21 on the side of a display surface and on thesurface of the glass substrate 22 on the side of the image displaysection 10 in the parallax barrier 20 of the liquid crystal system.

(Principles of Parallax Barrier System)

Principles of the parallax barrier system will be described in thefollowing. Incidentally, the parallax barrier system includes abinocular parallax system, a multi-parallax system with three or moreviewpoints, a step barrier system, and so on. Outlines of the principlesof the parallax barrier system will be described with reference to FIG.3 by taking the binocular parallax system as an example.

In the pixel array in the image display section 10 in the form of amatrix, pixels (sub-pixels) are divided in units of pixel columns into agroup of pixels R₁, R₃, R₅, R₇, and R₉ for the right eye used to displayan image for the right eye and a group of pixels L₂, L₄, L₆, L₈, and L₁₀for the left eye used to display an image for the left eye. In otherwords, the pixel array is such that the pixel columns of the group ofpixels R₁, R₃, R₅, R₇, and R₉ and the pixel columns of the group ofpixels L₂, L₄, L₆, L₈, and L₁₀ are arranged alternately.

A video signal for the right eye is supplied from a signal source (notshown) for the right eye to the group of pixels R₁, R₃, R₅, R₇, and R₉for the right eye in units of pixel columns. In addition, a video signalfor the left eye is supplied from a signal source (not shown) for theleft eye to the group of pixels L₂, L₄, L₆, L₈, and L₁₀ for the left eyein units of pixel columns. The two images of the image for the right eyeand the image for the left eye, that is, the parallax images can thus bedisplayed on the image display section 10.

In a state where the parallax images are being displayed on the imagedisplay section 10, as shown in FIG. 3A, a group of light rays emittedfrom the pixels R₁, R₃, R₅, R₇, and R₉ for the right eye reaches asecond viewpoint through the transmitting sections 25 of the parallaxbarrier 20. In addition, as shown in FIG. 3B, a group of light raysemitted from the pixels L₂, L₄, L₆, L₈, and L₁₀ for the left eye reachesa first viewpoint through the transmitting sections 25 of the parallaxbarrier 20.

Thus, the image for the first viewpoint and the image for the secondviewpoint are observed independently of each other at a position at apredetermined distance from the display surface of the image displaysection 10. Specifically, when the left eye and the right eye of animage observer are situated at the first viewpoint and the secondviewpoint, that is, when the image observer observes the images at theposition at the predetermined distance from the display surface of theimage display section 10, the parallax images displayed by the imagedisplay section 10 enter the left eye and the right eye of the imageobserver as the image for the left eye and the image for the right eye.As a result, a binocular parallax occurs, and the image observer canobserve (perceive) the parallax image displayed by the image displaysection 10 three-dimensionally, that is, as a stereoscopic image.

The principles of the parallax barrier system have been described aboveby taking as an example a case of a binocular parallax. In general, asshown in FIG. 4, the parallax barrier 20 acts to display a plurality ofimages by allocating the pixels (sub-pixels) in a pixel row to aplurality of viewpoints (four viewpoints in the present example)according to the respective positions of the viewpoints.

The principles of displaying an image by allocating pixels according tothe positions of viewpoints are similar to those of the lenticular lenssystem, the liquid crystal lens system, and the like. Thus, not only theparallax barrier 20 but also a lenticular lens, a liquid crystal lens,or the like can be used as the optical element for allocating lightemitted from the image display section 10 in units of sub-pixels to aplurality of viewpoints, or in other words, allocating the sub-pixelsaccording to the positions of the plurality of viewpoints.

In addition, in the above-described embodiment, the parallax barrier 20is disposed on the display surface side of the image display section 10.However, the parallax barrier 20 can be disposed on the side opposite tothe display surface of the image display section 10, that is, on adisplay rear surface side.

Further, in the above-described embodiment, a stereoscopic image displaydevice has been described. However, the present technology is applicableto display devices in general that display a plurality of images byallocating sub-pixels to a plurality of viewpoints according to therespective positions of the viewpoints, including, in addition tostereoscopic image display devices, two-screen display devices thatdisplay different images according to an angle at which the imagedisplay section is observed.

(Color Arrangement of Pixels of Image Display Section and Arrangement ofTransmitting Sections of Parallax Barrier)

In the image display section 10, one pixel as a unit forming a colorimage (i.e., a unit pixel) is composed of three sub-pixels correspondingto the three primary colors of RGB, for example (which sub-pixels mayhereinafter be referred to simply as “pixels”). These sub-pixelscorrespond to the pixels 40 shown in FIG. 1. The so-called stripearrangement in which the sub-pixels corresponding to the three primarycolors of RGB are arranged in units of pixel columns is generallyadopted as the color arrangement of the pixels 40 of the image displaysection 10.

The arrangement of the transmitting sections 25 of the parallax barrier20 includes a step barrier system, a delta (Δ) barrier system, astraight barrier (stripe barrier) system, and so on. In the following,the arrangement of the step barrier system may be referred to as a stepbarrier arrangement, the arrangement of the delta barrier system may bereferred to as a delta barrier arrangement, and the arrangement of thestraight barrier system may be referred to as a straight barrierarrangement. Incidentally, FIG. 1 shows the straight barrier arrangementin order to simplify the drawing.

Thus, the color arrangement of the pixels 40 of the image displaysection 10 and the arrangement of the transmitting sections 25 of theparallax barrier 20 each have regularity. This enables excellent imagedisplay when an ordinary planar image (two-dimensional image) isdisplayed. However, when a stereoscopic image (three-dimensional image)is displayed, the pixels allocated to each viewpoint are arrangedlinearly in color units for each viewpoint in a row (horizontal)direction, a column (vertical) direction, or an oblique direction, sothat a problem such as a deformation or absence of a character, coloringoccurs. This problem will be more concretely described in the following.

The problem in a case of three viewpoints will be described withreference to FIGS. 5A to 5C. FIG. 5A shows the stripe arrangement of thepixels 40 in the image display section 10. FIG. 5B shows the arrangementof the step barrier system of the transmitting sections 25 in theparallax barrier 20. FIG. 5C shows pixels allocated to the firstviewpoint. Numbers given in the pixels in FIGS. 5A and 5C representtheir viewpoint position. The same applies to diagrams of otherexamples.

According to such a combination of the stripe arrangement of the pixels40 in the image display section 10 and the step barrier arrangement ofthe transmitting sections 25 in the parallax barrier 20 in the case ofthree viewpoints, as shown in FIG. 5C, the pixels allocated to the firstviewpoint are arranged so as to continue linearly in the row direction(horizontal direction) and the column direction (vertical direction) incolor units. Thus, when a character or a figure or the like including ahorizontal straight line is displayed against a single background color,the character or the figure is deformed.

In order to facilitate understanding, an example where a Chinesecharacter (kanji) composed of a square and a plus therein (□ with +therein), made up of a set of straight lines, is displayed on a screenin black with a background color of green is described. This charactercan be displayed excellently in a case of display of a two-dimensional(2D) image, as shown in FIG. 6A. On the other hand, in a case of displayof a three-dimensional (3D) image, as shown in FIG. 6B, only onerow/column in every three rows/columns is allocated for each viewpoint.Thus, when the lines forming the character do not have a thickness ofthree or more rows/columns, there may be a missing part in thecharacter. Incidentally, FIG. 6B show an image arriving at the firstviewpoint (or pixels of G allocated to the first viewpoint).

In addition, in a case other than single-color display, for example acase where a black character is displayed on a screen with a backgroundcolor of white, when the character includes a horizontal line, thecharacter will have no missing part. However, unless three colors aredrawn together (unless line width is a multiple of three), or in otherwords, when one color or two colors remain, color balance is lost, sothat the character is colored (this is the so-called coloring).

The problem in a case of four viewpoints will next be described withreference to FIGS. 7A to 7C. FIG. 7A shows the stripe arrangement of thepixels 40 of the image display section 10. FIG. 7B shows the arrangementof the step barrier system of the transmitting sections 25 in theparallax barrier 20. FIG. 7C shows pixels allocated to the firstviewpoint at a time of white display.

According to such a combination of the stripe arrangement of the pixels40 of the image display section 10 and the step barrier arrangement ofthe transmitting sections 25 of the parallax barrier 20 in the case offour viewpoints, as shown in FIG. 7C, the pixels allocated to the firstviewpoint are arranged so as to continue linearly in an obliquedirection in color units. More specifically, the pixels allocated to thefirst viewpoint are arranged so as to continue linearly in an obliquedirection from a lower left (upper right) to an upper right (lowerleft). In this case as well, unless an oblique line has a thickness ofthree rows/three columns or more, the character may be chipped forreasons similar to those in the case of three viewpoints.

The problem in a case of four viewpoints where the pixels 40 of theimage display section 10 are in a stripe arrangement and thetransmitting sections 25 of the parallax barrier 20 are in a deltaarrangement will next be described with reference to FIGS. 8A to 8C.FIG. 8A shows the color arrangement of pixels allocated to the firstviewpoint at a time of white display. FIG. 8B shows the deltaarrangement of the transmitting sections 25 of the parallax barrier 20.FIG. 8C shows pixels allocated to the first viewpoint at a time ofsingle-color display (in this case, pixels of G).

As shown in FIG. 8B, the delta arrangement is formed by pairing twoupper and lower pixel rows as one set, and shifting transmittingsections 25 in the two pixel rows from each other by two pixels(sub-pixels). The pair of two upper and lower pixel rows are arranged soas to be repeated in the column direction.

In the case of this delta arrangement, the relation of the transmittingsections 25 in the pair of two upper and lower pixel rows forming adelta arrangement is arranged in a regular pattern between two upper andlower sets. Thus, as is clear from FIG. 8B, the transmitting sections 25of the parallax barrier 20 are arranged consecutively in a rowdirection, a column direction, and an oblique direction.

In such a case of arrangement for pixel allocation by the parallaxbarrier 20 in which the transmitting sections 25 are arrangedconsecutively in the row direction, the column direction, and theoblique direction, as shown in FIG. 8A, RGB combinations enclosed bywhite solid lines and RGB combinations enclosed by white broken lineseach form a stripe-shaped arrangement. When a single color (G in thepresent example) is viewed in this color arrangement, as shown in FIG.8C, the pixels of G allocated to the first viewpoint are arranged so asto continue linearly in the column direction (vertical direction).Therefore a vertical line included in a character or a geometric figuremay suffer such a problem that the character or the geometric figure isdeformed.

Referring to FIGS. 9A to 9C, further consideration will be given to thecase of FIGS. 7A to 7C, that is, the case of four viewpoints where thepixels 40 of the image display section 10 are in a stripe arrangementand the transmitting sections 25 of the parallax barrier 20 are in astep barrier arrangement. FIG. 9A shows the color arrangement of thepixels allocated to the first viewpoint at a time of white display,which corresponds to FIG. 7C. FIG. 9B shows the arrangement of thetransmitting sections 25 of the parallax barrier 20, which correspondsto FIG. 7B. FIG. 9C shows the pixels allocated to the first viewpoint ata time of single-color display (pixels of G in this example).

As shown in FIG. 9B, for the stripe arrangement of the image displaysection 10 shown in FIG. 7A, the transmitting sections 25 of theparallax barrier 20 have a step barrier arrangement with four rows as aunit, in which one pixel row has a period of four pixels (sub-pixels)and the transmitting sections 25 are shifted every pixel rowsequentially by one pixel in the row direction. This step barrierarrangement with four rows as a unit is arranged so as to be repeated inthe column direction. The transmitting sections 25 of the parallaxbarrier 20 thereby form an arrangement continuing in an obliquedirection.

Because of the consecutive arrangement of the transmitting sections 25,as shown in FIG. 9A, the color arrangement of the pixels allocated tothe first viewpoint as viewed from a same row is a monotone pattern inwhich repetitions of an RGB pixel group enclosed by a white solid line,a GBR pixel group enclosed by white alternate long and short dashedlines, and a BRG pixel group enclosed by a white broken line formoblique straight lines. When a single color (G in the present example)is viewed in the color arrangement of this monotone pattern, as shown inFIG. 9C, the single color is arranged consecutively in a certaindirection, that is, an oblique direction. Therefore, it is difficult toperform oblique display under the arrangement in which the single colorcontinues in the certain direction.

(Characteristic Parts of Embodiment)

In the stereoscopic image display device 1 according to the presentembodiment, the color arrangement of the pixels (sub-pixels) 40 of theimage display section 10 or the arrangement of the transmitting sections25 of the parallax barrier 20 is set as below in order to improvevisibility when displaying an image composed of a monotone set ofpixels, such as a geometric figure or a character in particular. Thetransmitting sections 25 of the parallax barrier 20 in this casecorrespond to the window section of the optical element for allocatinglight emitted from the image display section 10 in units of pixels(sub-pixels) 40 to a plurality of viewpoints, or in other words,allocating the sub-pixels to the plurality of viewpoints according tothe respective positions of the viewpoints.

Specifically, the color arrangement of the pixels (sub-pixels) of theimage display section 10 is set such that, when the image displaysection 10 is viewed from each of the plurality of viewpoints, in thearrangement of colors of light allocated by the transmitting sections 25of the parallax barrier 20, a same color is not arranged linearly in apredetermined number of sub-pixels or more in succession in the rowdirection, the column direction, or the oblique direction.Alternatively, the arrangement of the transmitting sections 25 of theparallax barrier 20 is set such that, when the image display section 10is viewed from each of the plurality of viewpoints, in the arrangementof colors of light allocated by the transmitting sections 25 of theparallax barrier 20, a same color is not arranged linearly in apredetermined number of sub-pixels or more in succession in the rowdirection, the column direction, or the oblique direction.

When a same color is not arranged linearly in a predetermined number ofsub-pixels or more in succession in the row direction, the columndirection, or the oblique direction in each of the arrangements ofcolors of light allocated by the transmitting sections 25 of theparallax barrier 20, that is, each of the arrangements observed when theimage display section 10 is viewed from each of the plurality ofviewpoints, the following effect can be obtained. The absence ofinformation in a same column, row, oblique direction, or the like can beavoided at a time of allocating images composed of a monotone set ofpixels to respective viewpoints. It is therefore possible to improvevisibility of when displaying images composed of a monotone set ofpixels, such as a geometric figure or a character in particular.

Here, a common example of a case where the transmitting sections 25 ofthe parallax barrier 20 have a step barrier arrangement as a basic formwith N viewpoints (N is a natural number of two or larger) is described.In related arts, as shown in FIG. 10A, the viewpoint position number issequentially decremented by one in the column direction in an RGB stripearrangement (corresponding to the case of four viewpoints shown in FIG.7A). In this case, as has also been described above, the pixels of asingle color allocated to each viewpoint are arranged linearly insuccession in the row direction, the column direction, or the obliquedirection, thus degrading visibility of when displaying an imagecomposed of a monotone set of pixels such for example as a geometricfigure or a character.

Meanwhile, in this embodiment, as shown in FIG. 10B, three rowscorresponding to three sub-pixels of RGB are set as one unit, and stepsare formed so as to be discontinuous in the column direction by shiftingviewpoint position numbers in the row direction. Alternatively, it isalso possible to change the color combination or the direction of thesteps of the step barrier arrangement. The adoption of such aconfiguration can improve visibility of when displaying an imagecomposed of a monotone set of pixels such for example as a geometricfigure or a character.

Description will be made in the following of concrete examples of thecolor arrangement of the pixels (sub-pixels) 40 in the image displaysection 10 and the arrangement of the transmitting sections 25 of theparallax barrier 20, which are designed to improve visibility of whendisplaying images composed of a monotone set of pixels such for exampleas a geometric figure or a character.

First Example

FIGS. 11A to 11C are diagrams for assistance in explaining the colorarrangement of the pixels in the image display section and thearrangement of the transmitting sections of the parallax barrier in thecase of four viewpoints according to a first example. FIG. 11A shows thecolor arrangement of the pixels allocated to the first viewpoint at atime of white display. FIG. 11B shows the arrangement of thetransmitting sections 25 of the parallax barrier 20. FIG. 11C shows thepixels allocated to the first viewpoint at a time of single-colordisplay (pixels of G in the present example). Numbers given in thepixels in FIGS. 11A and 11C represent viewpoint positions. The sameapplies to diagrams of other examples.

First, the color arrangement of the pixels (sub-pixels) 40 of the imagedisplay section 10 is the stripe arrangement shown in FIG. 7A.Specifically, the color arrangement of the pixels of the image displaysection 10 with four viewpoints is a stripe arrangement in whichsub-pixels of RGB are for example arranged in that order in units ofpixel columns. The sub-pixels of RGB may be arranged in any order. Thesame applies to the other examples.

For the stripe arrangement of this image display section 10, as shown inFIG. 11B, the transmitting sections 25 of the parallax barrier 20according to the first example have a step barrier arrangement in whichone pixel row has a period of four pixels (sub-pixels) corresponding tothe four viewpoints, and the transmitting sections 25 are shifted everypixel row by one pixel sequentially in a direction in which the pixelcolumn number increases (right direction in the figure). Further, inthis arrangement, three successive rows constitute one unit. This stepbarrier arrangement of three rows as one unit is arranged repetitivelyin the column direction such that they are shifted in order by one pixelin the direction in which pixel column numbers increase.

Thus, when the amount of shift (shift width) of steps is not fixed inthe case adopting the step barrier arrangement as a basic form, thetransmitting sections 25 of the parallax barrier 20 according to thefirst example will have such an arrangement that the steps arediscontinuous in an oblique direction with three rows as one unit.

Because of the discontinuous arrangement of the transmitting sections25, as shown in FIG. 11A, the color arrangement of the pixels allocatedto the first viewpoint as viewed from a same row will be a pattern inwhich an RGB pixel group enclosed by a white solid line, a GBR pixelgroup enclosed by white alternate long and short dashed lines, and a BRGpixel group enclosed by a white broken line are shifted in the rowdirection in the next repetition. When a single color (G in the presentexample) is viewed in the color arrangement, as shown in FIG. 11C, thesingle color is arranged linearly in certain directions, specificallythe column direction (vertical direction) and the oblique direction, butis not arranged in a predetermined number of sub-pixels (four sub-pixelsin the present example) or more in succession.

When a same color is thus not arranged linearly in a predeterminednumber of sub-pixels or more in succession in a certain direction in anarrangement of colors of light allocated by the transmitting sections 25of the parallax barrier 20 when the image display section 10 is viewedfrom each of the plurality of viewpoints, the absence of obliqueinformation can be avoided when allocating images composed of a monotoneset of pixels to the respective viewpoints. It is therefore possible toimprove visibility at a time displaying images composed of a monotoneset of pixels such for example as a geometric figure or a character inparticular.

Second Example

FIGS. 12A to 12C are diagrams for assistance in explaining the colorarrangement of the pixels of the image display section and thearrangement of the transmitting sections of the parallax barrier in thecase of four viewpoints according to a second example. FIG. 12A showsthe color arrangement of the pixels allocated to the first viewpoint ata time of white display. FIG. 12B shows the arrangement of thetransmitting sections 25 of the parallax barrier 20. FIG. 12C shows thepixels allocated to the first viewpoint at a time of single-colordisplay (pixels of G in the present example).

The color arrangement of the pixels (sub-pixels) 40 of the image displaysection 10 is similar to that of the first example. Specifically, asshown in FIG. 7A, the color arrangement of the pixels of the imagedisplay section 10 in the case of four viewpoints is the stripearrangement in which sub-pixels of RGB are for example arranged in thatorder in units of pixel columns.

For the stripe arrangement of the image display section 10, as shown inFIG. 12B, the transmitting sections 25 of the parallax barrier 20according to the second example have a step barrier arrangement of threerows as a unit, in which one pixel row has a period of four pixels(sub-pixels) corresponding to the four viewpoints, and the transmittingsections 25 are shifted every row in order by one pixel in the rowdirection. In addition, this step barrier arrangement in which threerows form one unit is such that the direction of the steps is reversedin the next three rows, and the next three rows are also shifted by onepixel in a direction in which the pixel column number increases (rightdirection in the figure). This unit of step barrier arrangementconstituted by a total of six rows is arranged so as to be repeated inthe column direction.

Thus, when the direction of steps is not fixed in the case where thestep barrier arrangement is a basic form, the transmitting sections 25of the parallax barrier 20 according to the second example are arrangedsuch that steps are discontinuous in an oblique direction with threerows as one unit.

Because of the discontinuous arrangement of the transmitting sections25, as shown in FIG. 12A, the color arrangement of the pixels allocatedto the first viewpoint as viewed from a same row is such that an RGBpixel group enclosed by a white solid line, a GBR pixel group enclosedby white alternate long and short dashed lines, and a BRG pixel groupenclosed by a white broken line is reversed in terms of the arrangementdirection of pixels in the next repetition. In addition, the colorarrangement of the pixels forms a pattern in which each pixel group ofthe next repetition is shifted by one pixel in the direction in whichpixel columns are increased. When a single color (G in the presentexample) is viewed in this color arrangement, as shown in FIG. 12C, thesingle color is arranged linearly in a certain direction, specificallythe oblique direction, but is not arranged in a predetermined number ofsub-pixels (five sub-pixels in the present example) or more insuccession.

When a same color is thus not arranged linearly in a predeterminednumber of sub-pixels or more in succession in a certain direction in anarrangement of colors of light allocated by the transmitting sections 25of the parallax barrier 20 observed when the image display section 10 isviewed from each of the plurality of viewpoints, the absence of obliqueinformation can be avoided at a time of allocating images composed of amonotone set of pixels to the respective viewpoints. It is thereforepossible to improve visibility of when displaying images composed of amonotone set of pixels such for example as a geometric figure or acharacter in particular.

Third Example

FIGS. 13A to 13C are diagrams for assistance in explaining relationbetween the color arrangement of the pixels of the image display sectionand the arrangement of the transmitting sections of the parallax barrierin the case of four viewpoints according to a third example. FIG. 13Ashows the color arrangement of the pixels allocated to the firstviewpoint at a time of white display. FIG. 13B shows the arrangement ofthe transmitting sections 25 of the parallax barrier 20. FIG. 13C showsthe pixels allocated to the first viewpoint at a time of single-colordisplay (pixels of G in the present example).

The color arrangement of the pixels (sub-pixels) 40 of the image displaysection 10 is similar to that of the first example. Specifically, asshown in FIG. 7A, the color arrangement of the pixels of the imagedisplay section 10 in the case of four viewpoints is the stripearrangement in which sub-pixels of RGB are for example arranged in thatorder in units of pixel columns.

For the stripe arrangement of the image display section 10, as shown inFIG. 13B, the transmitting sections 25 of the parallax barrier 20according to the third example have a step barrier arrangement of threerows as one unit, in which one pixel row has a period of four pixels(sub-pixels) corresponding to the four viewpoints and the transmittingsections 25 are shifted every pixel row in order by one pixel in the rowdirection. This step barrier arrangement as one unit formed of threerows is arranged in the next three rows such that the direction of thesteps is reversed, and also the next three rows are shifted by one pixelin a direction in which pixel columns are decreased (left direction inthe figure). The step barrier arrangement of a total of six rows as aunit is arranged so as to be repeated in the column direction.

Thus, when the amount of shift (shift width) of steps and the directionof steps are not fixed in the case where the step barrier arrangement isa basic form, the transmitting sections 25 of the parallax barrier 20according to the third example are arranged such that steps arediscontinuous in an oblique direction with three rows as one unit.

Because of the discontinuous arrangement of the transmitting sections25, as shown in FIG. 13A, the color arrangement of the pixels allocatedto the first viewpoint as viewed from a same row is such that an RGBpixel group enclosed by a white solid line, a GBR pixel group enclosedby white alternate long and short dashed lines, and a BRG pixel groupenclosed by a white broken line have a reversed pixel arrangementdirection in the next repetition. In addition, the color arrangement ofthe pixels forms a complex pattern in which each pixel group in the nextrepetition is shifted by one pixel in the direction in which pixelcolumns are decreased. When a single color (G in the present example) isviewed in this color arrangement, as shown in FIG. 13C, the single coloris arranged linearly in a certain direction, specifically the obliquedirection, but is not arranged in a predetermined number of sub-pixels(four sub-pixels in the present example) or more in succession.

When a same color is thus not arranged linearly in a predeterminednumber of sub-pixels or more in succession in the oblique direction inan arrangement of colors of light allocated by the transmitting sections25 of the parallax barrier 20 observed when the image display section 10is viewed from each of the plurality of viewpoints, the absence ofoblique information can be avoided at a time an image composed of amonotone set of pixels is allocated to the respective viewpoints. It istherefore possible to improve visibility of when displaying imagescomposed of a monotone set of pixels such for example as a geometricfigure or a character in particular.

Fourth Example

FIGS. 14A to 14C are diagrams for assistance in explaining relationbetween the color arrangement of the pixels of the image display sectionand the arrangement of the transmitting sections of the parallax barrierin the case of four viewpoints according to a fourth example. FIG. 14Ashows the color arrangement of the pixels allocated to the firstviewpoint at a time of white display. FIG. 14B shows the arrangement ofthe transmitting sections 25 of the parallax barrier 20. FIG. 14C showsthe pixels allocated to the first viewpoint at a time of single-colordisplay (pixels of G in the present example).

The arrangement of the transmitting sections 25 of the parallax barrier20 according to the fourth example is positioned as a modification ofthe arrangement of the transmitting sections 25 of the parallax barrier20 according to the third example. Specifically, in the arrangement ofthe transmitting sections 25 of the parallax barrier 20 according to thethird example, three successive rows form one unit, and in the nextrepetition the direction of steps of the unit is reversed while the unitis shifted by one pixel in the direction in which the pixel columnnumber decreases. This step barrier arrangement formed of a total of sixrows as one unit is arranged so as to be repeated in the columndirection.

On the other hand, in the arrangement of the transmitting sections 25 ofthe parallax barrier 20 according to the fourth example, the stepbarrier arrangement in which three rows form one unit is configured suchthat the direction of shifting, amount of shifting in pixel units,and/or the reversal (change) of the direction of steps are combinedarbitrarily with each other in units of three rows. By adopting such aconfiguration, the transmitting sections 25 of the parallax barrier 20according to the fourth example are arranged so as to be discontinuousin an oblique direction with three rows as a unit.

Because of the discontinuous arrangement of the transmitting sections 25as shown in FIG. 14B, as shown in FIG. 14A, the color arrangement of thepixels allocated to the first viewpoint is a complex pattern in whichfirst six rows are the same as those in the third example but thesubsequent color arrangement is different from that of the first sixrows. When a single color (G in the present example) is viewed in thiscolor arrangement, as shown in FIG. 14C, the single color is arrangedlinearly in a certain direction, specifically the oblique direction, butis not arranged in a predetermined number of sub-pixels (five sub-pixelsin the present example) or more in succession.

When a same color is thus not arranged linearly in a predeterminednumber of sub-pixels or more in succession in the oblique direction ineach of the arrangements of colors of light allocated by thetransmitting sections 25 of the parallax barrier 20, that is, in each ofthe arrangements observed when the image display section 10 is viewedfrom each of the plurality of viewpoints, the absence of obliqueinformation can be avoided at a time of allocating images composed of amonotone set of pixels to the respective viewpoints. It is thereforepossible to improve visibility when displaying images composed of amonotone set of pixels such for example as a geometric figure or acharacter in particular.

In the first to fourth examples described above, the step barrierarrangement is adopted as a basic form of the arrangement of thetransmitting sections 25 of the parallax barrier 20. However, a similaridea can be applied also to a case where the delta arrangement shown inFIG. 8B is adopted as a basic form. A case employing the parallaxbarrier 20 of the delta arrangement will be described as a fifthexample.

Fifth Example

FIGS. 15A to 15C are diagrams for assistance in explaining relationbetween the color arrangement of the pixels of the image display sectionand the arrangement of the transmitting sections of the parallax barrierin the case of four viewpoints according to the fifth example. FIG. 15Ashows the color arrangement of the pixels allocated to the firstviewpoint at a time of white display. FIG. 15B shows the arrangement ofthe transmitting sections 25 of the parallax barrier 20. FIG. 15C showsthe pixels allocated to the first viewpoint at a time of single-colordisplay (pixels of G in the present example).

The color arrangement of the pixels (sub-pixels) 40 of the image displaysection 10 is similar to that of the first example. Specifically, asshown in FIG. 7A, the color arrangement of the pixels of the imagedisplay section 10 in the case of four viewpoints is the stripearrangement in which sub-pixels of RGB are for example arranged in thatorder in units of pixel columns.

For the stripe arrangement of the image display section 10, as shown inFIG. 15B, the transmitting sections 25 of the parallax barrier 20according to the fifth example have such an arrangement relation that,when two upper and lower pixel rows are assumed as a pair, two upper andlower pairs are shifted from each other by three (or one) pixels(sub-pixels) in the row direction. Thus, as is clear from FIG. 15B, thetransmitting sections 25 are arranged so as to be discontinuous in thecolumn direction and the oblique direction.

In the case of the arrangement for thus allocating the pixels by theparallax barrier 20 in which the transmitting sections 25 are arrangedto be discontinuous in the column direction and the oblique direction,as shown in FIG. 15A, RGB combinations enclosed by white solid lines andRGB combinations enclosed by white broken lines are shifted in the rowdirection between upper and lower pairs. When a single color (G in thepresent example) is viewed in this color arrangement, as shown in FIG.15C, the pixels of G allocated to the first viewpoint are arranged in ascattered manner, and they are not arranged in succession in a certaindirection. Therefore, effects similar to those of the first to fourthexamples can be obtained.

In the first to fifth examples described above, while the known stripearrangement is adopted as a basic form of the color arrangement of thepixels 40, the absence of information is avoided at a time of allocatingimages composed of a monotone set of pixels to respective viewpoints byadapting the arrangement of the transmitting sections 25 of the parallaxbarrier 20. On the other hand, in a sixth example and a seventh exampledescribed below, similar effects are obtained by adapting the colorarrangement of the pixels 40 while a known arrangement is adopted forthe transmitting sections 25 of the parallax barrier 20.

Sixth Example

FIGS. 16A to 16C are diagrams for assistance in explaining relationbetween the color arrangement of the pixels of the image display sectionand the arrangement of the transmitting sections of the parallax barrierin the case of four viewpoints according to a sixth example. FIG. 16Ashows the color arrangement of the pixels allocated to the firstviewpoint at a time of white display. FIG. 16B shows the arrangement ofthe transmitting sections 25 of the parallax barrier 20. FIG. 16C showsthe pixels allocated to the first viewpoint at a time of single-colordisplay (pixels of G in the present example).

The arrangement of the transmitting sections 25 of the parallax barrier20 is a well-known step barrier arrangement. Specifically, as shown inFIG. 16B, the arrangement is a step barrier arrangement in which onepixel row has a period of four pixels (sub-pixels) corresponding to thefour viewpoints and the transmitting sections 25 are shifted every pixelrow sequentially by one pixel in a direction in which pixel columnnumber increases (right direction in the figure).

For this step barrier arrangement of the transmitting sections 25 of theparallax barrier 20, as shown in FIG. 16A, the color arrangement of thepixels 40 of the image display section 10 according to the sixth examplehas sub-pixels of RGB arranged for example in that order so as to berepeated in units of pixel columns, and three successive rows form oneunit. The three pixel rows are arranged repetitively in the columndirection such that the repeated units are shifted in order by twopixels (sub-pixels) in a direction in which the pixel column numberincreases. The color arrangement of the pixels 40 of the image displaysection 10 according to the sixth example is therefore an arrangementdiscontinuous in the column direction.

Because of the discontinuous color arrangement of the pixels 40, asshown in FIG. 16A, the color arrangement of the pixels allocated to thefirst viewpoint as viewed from a same row is such that an RGB pixelgroup enclosed by a black solid line, a GBR pixel group enclosed byblack alternate long and short dashed lines, and a BRG pixel groupenclosed by a black broken line are shifted in the row direction in thenext repetition. When a single color (G in the present example) isviewed in the color arrangement, as shown in FIG. 16C, the single coloris arranged linearly in a certain direction, specifically the obliquedirection, but is not arranged in a predetermined number of sub-pixels(four sub-pixels in the present example) or more in succession.Therefore, effects similar to those of the first to fifth examples canbe obtained.

Seventh Example

FIGS. 17A to 17C are diagrams for assistance in explaining relationbetween the color arrangement of the pixels of the image display sectionand the arrangement of the transmitting sections of the parallax barrierin the case of four viewpoints according to a seventh example. FIG. 17Ashows the color arrangement of the pixels allocated to the firstviewpoint at a time of white display. FIG. 17B shows the arrangement ofthe transmitting sections 25 of the parallax barrier 20. FIG. 17C showsthe pixels allocated to the first viewpoint at a time of single-colordisplay (pixels of G in the present example).

As shown in FIG. 17B, the arrangement of the transmitting sections 25 ofthe parallax barrier 20 is a well-known straight barrier (stripebarrier) arrangement. For this straight barrier arrangement of thetransmitting sections 25, as shown in FIG. 17A, the color arrangement ofthe pixels 40 of the image display section 10 according to the seventhexample is such that, in one row, sub-pixels of RGB are arranged forexample in that order repeatedly. Such a pixel row is repeatedlyarranged in the column direction while each row is sequentially shiftedby two pixels (sub-pixels) in the direction in which the pixel columnnumber increases. The color arrangement of the pixels 40 of the imagedisplay section 10 according to the seventh example is therefore suchthat sub-pixels of RGB are also repeated in that order in the columndirection, similarly to those in the row direction.

In this case as well, where the straight arrangement barrier of thetransmitting sections 25 and the color arrangement of the pixels 40according to the seventh example are combined, when a single color (G inthe present example) is viewed, as shown in FIG. 17C, the single coloris arranged linearly in a certain direction, specifically the obliquedirection, but is not arranged in a predetermined number of sub-pixels(four sub-pixels in the present example) or more in succession. Effectssimilar to those of the first to fifth examples can therefore beobtained. Particularly, since the transmitting sections 25 of theparallax barrier 20 are in the straight barrier arrangement, it ispossible not only to avoid the absence (loss) of an image or the likebut also to obtain a display panel with a wide range of visibility inthe vertical direction as a panel for stereoscopic image display.

Eighth Example

An eighth example will next be described with reference to FIGS. 18A to18D. As shown in FIG. 18A, the color arrangement of the pixels 40 of theimage display section 10 according to the eighth example is a horizontalstripe arrangement obtained by rotating 90 degrees a vertical stripearrangement (see FIG. 7A) formed by arranging sub-pixels of RGB, forexample, in that order.

The horizontal stripe arrangement has sets of sub-pixels of RGB arrangedin the vertical direction. Therefore, a parallax barrier having astraight barrier arrangement as shown in FIG. 18B may be used as theparallax barrier 20. Circles attached to the unit pixels in FIGS. 18B,18C, and 18D correspond to the transmitting sections 25 of the parallaxbarrier 20.

Thus, when the parallax barrier 20 of the straight barrier arrangementis used for the image display section 10 of the horizontal stripearrangement, the sub-pixels may often be allocated to respectiveviewpoints in a manner as shown in FIG. 18B in a case of multipleparallaxes. However, when such a configuration is adopted, N−1consecutive columns are not displayed in a case of N viewpoints (N=4 inthe present example). In a case of four viewpoints, for example,supposing that a first column is viewed, the pixels of the second tofourth columns are missing. Thus, the three columns (N−1 consecutivecolumns for N viewpoints) are missing (not displayed).

Accordingly, in the eighth example, as shown in FIG. 18C, thetransmitting sections 25 of the parallax barrier 20 are in a stepbarrier arrangement in which three sub-pixels of RGB are set as oneunit, and such units are distributed stepwise for each viewpoint with ashift in the row direction by one unit in order. Alternatively, thetransmitting sections 25 of the parallax barrier 20 are in adiscontinuous step barrier arrangement as shown in FIG. 18D.

The configuration thus combining the image display section 10 of thehorizontal stripe arrangement with the parallax barrier 20 of the stepbarrier arrangement can also provide effects similar to those of thefirst to fifth examples.

Ninth Example

FIGS. 19A to 19C are diagrams for assistance in explaining relationbetween the color arrangement of the pixels of the image display sectionand the arrangement of the transmitting sections of the parallax barrierin the case of four viewpoints according to a ninth example. FIG. 19Ashows the color arrangement of the pixels (sub-pixels) of the imagedisplay section 10. FIGS. 19B and 19C show arrangements of thetransmitting sections 25 of the parallax barrier 20.

As shown in FIG. 19A, the color arrangement of the pixels (sub-pixels)40 of the image display section 10 is the same as in the first to fifthexamples, that is, a stripe arrangement in which sub-pixels of RGB arefor example arranged in that order in units of pixel columns. On theother hand, the arrangement of the transmitting sections 25 of theparallax barrier 20 according to the ninth example is a step barrierarrangement in which two left and right transmitting sections 25 form apair so that two consecutive sub-pixels are allocated for a sameviewpoint image.

As a step barrier arrangement in which two left and right transmittingsections are paired, as shown in FIG. 19B, a step barrier arrangementwith continuous steps, in which two left and right transmitting sections25 form a pair and shifted every pixel row sequentially by one pixel(sub-pixel), is generally conceivable.

On the other hand, the arrangement of the transmitting sections 25 ofthe parallax barrier 20 according to the ninth example is such thatthree pixel rows form one set so as to correspond to the threesub-pixels of RGB. In the set of three pixel rows, steps are formed byshifting pairs of two left and right transmitting sections 25 by onepixel row by row. Between sets of three rows, steps are formed byshifting pairs of two left and right transmitting sections 25 by twopixels set by set. Therefore, as shown in FIG. 19C, the parallax barrier20 according to the ninth example has a step barrier arrangement withdiscontinuous steps.

Such a combination of the image display section 10 having the verticalstripe arrangement and the parallax barrier 20 allocating a plurality ofconsecutive sub-pixels for a same viewpoint image by the step barrierarrangement with discontinuous steps can also provide effects similar tothose of the first and fifth examples. The number of consecutivesub-pixels allocated for a same viewpoint image is two in the abovedescription. However, the same is true for three or more consecutivesub-pixels.

(Modifications)

The first to ninth examples have been described above by taking as anexample a case where a unit pixel which is one unit for forming a colorimage is composed of a combination of three sub-pixels corresponding tothe three primary colors of RGB. However, the present technology is notlimited to this. Examples of other possible combinations are thoseincluding another sub-pixel corresponding to another color in additionto the three sub-pixels corresponding to the three primary colors ofRGB. The additional sub-pixel may be a sub-pixel corresponding to white(W) as shown in FIG. 20A, or one corresponding to yellow (Y) as shown inFIG. 20B.

Other than the combination of three sub-pixels corresponding to thethree primary colors of RGB, a unit pixel may be constituted by acombination of sub-pixels corresponding to complementary colors of cyan(C), magenta (M), and yellow (Y), for example.

Further, in the first to ninth examples, the stripe arrangement isadopted as a basic form of the color arrangement of the pixels(sub-pixels) 40 of the image display section 10. However, the same as inthe stripe arrangement applies also to the delta arrangement and otherkinds of arrangements.

Embodiments of the present disclosure may take the followingconfigurations.

(1) A display device including:

an image display section in which unit pixels each composed of aplurality of sub-pixels corresponding to a plurality of colors arearranged; and

an optical element having a window section allocating light emitted fromthe image display section in units of the sub-pixels to a plurality ofviewpoints,

wherein a color arrangement of the sub-pixels of the image displaysection or an arrangement of the window section of the optical elementis set such that, when the image display section is viewed from each ofthe plurality of viewpoints, in an arrangement of colors of lightallocated by the window section of the optical element, a same color isnot arranged linearly in a predetermined number of sub-pixels or more insuccession in any of a row direction, a column direction, and an obliquedirection.

(2) The display device according to (1), wherein the image displaysection displays a plurality of images with parallax.

(3) The display device according to (2), wherein the optical element isa parallax barrier, a lenticular lens, or a liquid crystal lens.

(4) The display device according to any one of (1) to (3), wherein astripe arrangement is a basic form of the color arrangement of thesub-pixels in the image display section.

(5) The display device according to (3) or (4), wherein, when theoptical element is the parallax barrier, a step barrier arrangement or adelta arrangement is a basic form of transmitting sections of theparallax barrier.

(6) The display device according to (5), wherein, when the transmittingsections of the parallax barrier are in the step barrier arrangement,steps of the step barrier arrangement are arranged so as to bediscontinuous.

(7) The display device according to any one of (1) to (6), wherein theoptical element provides a plurality of images displayed by the imagedisplay section three-dimensionally to an image observer.

(8) The display device according to any one of (1) to (6), wherein theoptical element provides a plurality of images displayed by the imagedisplay section separately to a plurality of image observers.

The present disclosure contains subject matter related to that disclosedin Japanese Priority Patent Application JP 2011-230300 filed in theJapan Patent Office on Oct. 20, 2011, the entire content of which ishereby incorporated by reference.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

What is claimed is:
 1. A display device comprising: an image displaysection in which a plurality of RGB sub-pixels are arranged; and anoptical element allocating light emitted from the image display sectionof the RGB sub-pixels to a plurality of viewpoints, wherein the opticalelement is controlled such that each RGB sub-pixel is associated with arespective viewpoint, a color of each RGB sub-pixel in a respectiveviewpoint is different from a color of an adjacent RGB sub-pixel in therespective viewpoint in both the row direction and the column direction.2. The display device according to claim 1, wherein the image displaysection displays a plurality of images with parallax.
 3. The displaydevice according to claim 1, wherein the optical element is a parallaxbarrier, a lenticular lens, or a liquid crystal lens.
 4. The displaydevice according to claim 1, wherein the optical element has a windowsection which is arranged in an oblique direction.
 5. The display deviceaccording to claim 1, wherein the optical element is parallax barrier,and a step barrier arrangement or a delta arrangement is a form oftransmitting sections of the parallax barrier.
 6. The display deviceaccording to claim 5, wherein when the transmitting sections of theparallax barrier are in the step barrier arrangement, steps of the stepbarrier arrangement are arranged so as to be discontinuous.
 7. Thedisplay device according to claim 1, wherein the optical elementprovides a plurality of images displayed by the image display sectionthree-dimensionally to an image observer.
 8. The display deviceaccording to claim 1, wherein the optical element provides a pluralityof images displayed by the image display section separately to aplurality of image observers.
 9. A display device comprising: an imagedisplay section in which a plurality of RGB sub-pixels are arranged; andan optical element allocating light emitted from the image displaysection of the RGB sub-pixels to a plurality of viewpoints, wherein acolor arrangement of the sub-pixels of the image display section or anarrangement of the optical element is set such that, when the imagedisplay section is viewed from each of the plurality of viewpoints, inan arrangement of colors of light allocated by the optical element, asame color is not arranged linearly in a predetermined number ofsub-pixels or more in succession in any of a row direction, a columndirection, and an oblique direction.
 10. The display device according toclaim 9, wherein the image display section displays a plurality ofimages with parallax.
 11. The display device according to claim 9,wherein the optical element is a parallax barrier, a lenticular lens, ora liquid crystal lens.
 12. The display device according to claim 9,wherein the optical element has a window section which is arranged in anoblique direction.
 13. The display device according to claim 9, whereinthe optical element is a parallax barrier, and a step barrierarrangement or a delta arrangement is a form of transmitting sections ofthe parallax barrier.
 14. The display device according to claim 13,wherein when the transmitting sections of the parallax barrier are inthe step barrier arrangement, steps of the step barrier arrangement arearranged so as to be discontinuous.
 15. The display device according toclaim 9, wherein the optical element provides a plurality of imagesdisplayed by the image display section three-dimensionally to an imageobserver.
 16. The display device according to claim 1, wherein theoptical element provides a plurality of images displayed by the imagedisplay section separately to a plurality of image observers.
 17. Adisplay device comprising: an image display section in which a pluralityof RGB sub-pixels are arranged; and an optical element allowing a viewerat a plurality of viewpoints to view colors of the RGB sub-pixels,wherein the RGB sub-pixels are arranged on the image display sectionsuch that, each RGB sub-pixel is associated with a respective viewpoint,a color of each RGB sub-pixels in the respective viewpoint is differentfrom a color of an adjacent RGB sub-pixel in the respective viewpoint inboth the row direction and column direction.